Reserved Multicast Addresses; Igmp Version 3 - Alcatel OmniSwitch 6624 Network Configuration Manual

IPMS Overview

Reserved Multicast Addresses

The Internet Assigned Numbers Authority (IANA) created the range for multicast addresses, which is
224.0.0.0 to 239.255.255.255. However, as the table below shows, certain addresses are reserved and
cannot be used.
Address or Address Range
224.0.0.0 through 224.0.0.255
224.0.1.0 through 224.0.1.255
224.0.2.0 through 224.0.255.0
224.1.0.0 through 224.1.255.255
224.2.0.0 through 224.2.255.255
224.252.000.000 through 224.255.255.255
225.000.000.000 through 231.255.255.255
232.000.000.000 through 232.255.255.255
233.000.000.000 through 233.255.255.255
234.000.000.000 through 238.255.255.255
239.000.000.000 through 239.255.255.255

IGMP Version 3

IGMP is used by IPv4 systems (hosts and routers) to report their IP multicast group memberships to any
neighboring multicast routers. IGMP version 2 (IGMPv2) handles forwarding by IP multicast destination
address only. IGMP version 3 (IGMPv3) handles forwarding by source IP address and IP multicast desti-
nation address. OmniSwitch 6600 Series switches support IGMPv2 and IGMPv3.
Note. See "Configuring the IGMP Proxy Version" on page 23-6
version.
In IGMPv2, each membership report contains only one multicast group. In IGMPv3, membership reports
contain many multicast groups up to the Maximum Transmission Unit (MTU) size of the interface.
IGMPv3 uses source filtering and reports multicast memberships to neighboring routers by sending
membership reports.
page 23-4
Description
Routing protocols (e.g., OSPF, RIP2)
Internetwork Control Block (e.g., RSVP, DHCP, commer-
cial servers)
AD-HOC Block (e.g., commercial servers)
ST Multicast Groups
SDP/SAP Block
DIS Transient Groups
Reserved
Source Specific Multicast
GLOP Block
Reserved
Administratively Scoped
for information on configuring the IGMP
OmniSwitch 6624/6648 Network Configuration Guide
Configuring IP Multicast Switching
April 2004